Abstract
A trend survey was conducted on 112 patients with cleft palate among patients with cleft lip and palate（CL/CP）who had visited the orthodontic clinic at Chiba Hospital of Tokyo Dental College in the 40 years from 1975 to 2014. Patients with cleft palate with accompanying syndromes were excluded. The results were as follows.
1. The number of patients by age increased from 1980 to 1994；no specific increase or decrease was recognized thereafter. The ratio of male to female patients with cleft palate was 1：1.24.
2. At first visit, many of the patients（18.8％）were 8 years old, and the majority（55.4％）were 7 to 10 years old.
3. Patients with congenitally missing permanent teeth accounted for 38.4％ of the cases. Classes of congenitally missing teeth were more frequent in the order of：upper lateral incisors（37.7％）, maxillary second premolars（34.8％）, and mandibular premolars（15.9％）. The breakdown of congenitally missing teeth was 73.9％ in the upper jaw and 26.1％ in the lower jaw.
4. Morphological evaluation using cephalogram at the first visit revealed poor growth of the maxilla and retroclination of mandibular central incisors. The inter-incisal angle was significantly larger than the reference value. Patients who had positive anterior tooth overjet accounted for 67.5％ of the cases, and those with negative overjet for 32.5％.
5. The devices most frequently selected were the expansion plate of orthodontic appliance（33.8％）and quad helix （31.3％）. Nineteen patients（38.0％）had tooth extraction at PhaseⅡ. Only 9 patients（32.1％）had tooth extraction at PhaseⅡamong 28 patients who were treated from PhaseⅠ. Ten patients（45.5％）had tooth extraction among 22 patients who started from PhaseⅡwithout PhaseⅠ.
